• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.4
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• pp.407-413
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• 1999

Maxillary duplication is a kind of proliferative neurocristopathy and considered to arise from bifurcation of neural crest elements soon after migration into mandibular arch. Sometimes this malformation is accompanied with oblique facial cleft. Usually this type of maxillofacial malformation requires multiple surgical intervention and the results are far from ideal. It became more troublesome if it had not been properly corrected on time, because secondary deformities could be developed from growth and development of abnormal tissues. This is a case of a 25-year-old-female patient who showed severe facial asymmetry thought to secondary deformity of maxillary duplication and masticatory disturbance due to multiple supernumerary teeth on posterior part right maxilla. We successully treated these deformities through four times of surgery of bone resection, orthodontic treatment, zygomatic and orbital reconstruction, orthognathic surgery and scar revision... ect. So we reported this rare case with review of literatures.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.1
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• pp.23-29
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• 2009

The ovate pontic was first described by Dewey and Zugsmith in 1933, but used clinically as a clinical alternative for esthetics in the late 1990s. The ovate pontic has been suggested as a more accurate duplication of emergence profile for natural teeth to provide an esthetic, cleanable prosthesis. If the resin temporary prosthesis with the ovate pontic is used during the healing period after the tooth extraction, it is possible to preserve the interdental papilla and eliminate or minimize the black triangle between the teeth. Ultimately it can become a esthetic final restoration without saliva leakage and phonetic discomfort. In this case we tried to treat the maxillary anterior area by the use of the ovate pontic and minimize the loss of the interdental papilla via duplicate the emergence profile of the natural tooth.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.195-204
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• 2008

Orthodontic brackets often need to be bonded to porcelain such as porcelain fused to metal crowns and porcelain jacket crowns. The purpose of this study was to evaluate the clinical usability of direct bonding system on porcelain teeth by measuring shear bond strength according to various conditions and observing adhesive failure patterns. The specimens, 20 maxillary premolars and 80 porcelain teeth that were produced by duplication of the labial surface of a maxillary first premolar were used and randomly divided into four groups of twenty teeth each. The 5 different preparation procedures tested: (1) application of 37% phosphoric acid on natural teeth, (2) sandblasting on porcelain surfaces, (3) sandblasting and application of 9.6% hydrofluoric acid on porcelain surfaces, (4) sandblasting and application of silane on porcelain surface, (5) sandblasting and application of 9.6% hydrofluoric acid and silane on porcelain surfaces. The metal brackets were bonded with Transbond $XT^{(R)}$ bonding material. The shear bond strength was tested by the micro universal testing machine(Kyung-Sung, Korea) and the amount of residual adhesive on the tooth surface after debonding was examined by stereoscope and assessed with an adhesive remnant index. The results of this study suggest that the direct bonding system on porcelain teeth with sandblasting, HF and porcelain primer is clinically useful.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.4
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• pp.454-464
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• 1999

The metal ceramic crown is currently the most popular complete veneer restoration in dentistry, but in many cases, the metal cervical collar at the facial margin is unesthetic and unacceptable. Facial porcelain margin has been used in place of it. But this dose not solve the problems, such as dark gingival discoloration and cervical opaque reflection of porcelain veneer. Recently, metal copings which were designed to terminate its labio-cervical end on the axial walls coronal to the shoulder have been clinically used to solve the esthetic problem of metal ceramic crown. But in this design, porcelain veneer of labio-cervical area which is not supported by metal may not be able to resist the stress during cementation and mastication. The purpose of this study was to evaluate fracture strength and fractured appearance of crowns according to different coping designs. A resin maxillary left central incisor analogue was prepared for a metal ceramic crown, and metal dies were made with duplication mold. Metal copings were made and assigned to one of four groups based on facial framework designs: group 1, coping with 0.5mm metal collar; group 2, metal extended to the shoulder; group 3, metal extended to 1mm coronal tn the shoulder: group 4, metal extended to 2mm coronal to the shoulder. Copings and crowns were adjusted to be same size and thickness, and cemented to metal dies with zinc phosphate cement by finger pressure. Fracture strength was measured with Instron Universal Testing Machine. Metal dies were anchored in Three-way-vice at 3mm below finish line and at $130^{\circ}$ inclined to the long axis of the crown. Load was directed lingually at 2mm below midincisal edge. Load value at initial crack and at catastrophic fracture was recorded. The results obtained were as follows : 1. Fracture strength values at initial crack were higher in groups 1, 2 than in groups 3, 4 but this difference was not statistically significant(P<0.05). 2. Conventional metal collared crown had greater catastrophic fracture strength than any other collarless crowns. 3. The greater the labial metal coping reduction, the lower the catastrophic fracture strength of crowns but when more than 1mm of labial metal reduction was done, the difference in strengths was not statistically significant(p<0.05). 4. The strongest collarless coping design was group 2.